Water Hyacinth (Eichhornia Crassipes), Any Oppor- Tunities for the Alaotra Wetlands and Livelihoods?

MADAGASCAR CONSERVATION & DEVELOPMENT VOLUME 1 0 | ISSUE S3 — OCTOBER 201 5 PAGE 1 28 ARTICLE http://dx.doi.org/1 0.431 4/mcd.v1 0i3s.5 Water hyacinth (Eichhornia crassipes), any opportunities for the Alaotra wetlands and livelihoods? Tsiry F. RakotoarisoaI, Patrick O. WaeberII, III, Torsten Correspondence: RichterI, Jasmin Mantilla-ContrerasI Tsiry F. Rakotoarisoa Ecology and Environmental Education Group, Institute of Biology and Chemistry, Hildesheim, Germany E-mail: [email protected] ABSTRACT institutionnelles et financières de Madagascar. L’utilisation de la Species invasions are one of the world’s most severe conserva- jacinthe d’eau, comme fertilisants, fourrage ou dans la production tion threats. The invasive water hyacinth (Eichhornia crassipes) is artisanale, pourrait représenter une alternative pour améliorer les one of the most troublesome plants in the world. It appears in moyens de subsistance de la population locale. Au cours de cette over 50 tropical and subtropical countries. This plant species étude, des données socioéconomiques touchant les parties pre- causes several ecological and socioeconomic problems affecting nantes des zones humides de l’Alaotra ont été collectées dans ecosystems and local livelihoods. The water hyacinth occurs in trois localités qui se différencient au niveau de la dégradation de the Alaotra wetlands encompassing the largest lake of Mada- l’habitat naturel (Anororo, Andreba et Vohimarina). Les objectifs de gascar. The Alaotra region is renowned as Madagascar’s bread cette recherche consistent d’une part à décrire des différents basket as it is the biggest rice and inland fish producer. The cur- moyens de subsistance locale et d’autre part à identifier les mo- rent study collected socioeconomic data from the Alaotra wetland teurs et barrières de l’utilisation de la jacinthe d’eau. Le contexte stakeholders within three locations around Lake Alaotra to général affectant la sécurité des moyens de subsistance pourrait contextualize local livelihoods and to identify the drivers and bar- bloquer l’acceptation de l’utilisation de cette plante. Cependant riers for the utilization of this plant. Methods of control seem to be l’information ainsi que des supports financiers et techniques pour unrealistic due to institutional and financial limitations in Mada- les parties prenantes locales sont des moteurs importants pour gascar. Using the plant as fertilizer, animal fodder or for handi- encourager l’usage de la jacinthe d’eau au niveau du lac Alaotra. crafts seems to represent a feasible alternative to improve the livelihood of the local population. However, local concerns about INTRODUCTION livelihood security may hinder acceptance of such new alterna- The water hyacinth (Eichhornia crassipes, Pontederiaceae) is an tives. Providing information as well as financial and technical sup- aquatic plant, originating from the Amazon Basin. It is listed by port to local stakeholders may help encourage the use of the IUCN as one of the “1 00 most invasive species” in the world (Lowe water hyacinth in the Alaotra region. et al. 2000) due to its high reproduction rate, the complex root structure and the formation of dense mats with up to two million RÉSUMÉ plants per hectare (Gopal 1 987, Villamagna and Murphy 201 0). The Les espèces envahissantes ont été récemment identifiées comme water hyacinth is to date recognized as invasive in over 50 tropi- l’une des principales menaces pour la protection de la biodiversi- cal and sub-tropical countries on five continents (Africa, Australia, té. La jacinthe d’eau (Eichhornia crassipes) est l’une des plantes Asia and America and for Europe in Portugal) (Gopal 1 987, Vil- envahissantes les plus problématiques au monde. Elle est connue lamagna and Murphy 201 0). The spreading of the plant can lead to dans plus de 50 pays tropicaux et subtropicaux. Cette plante est great ecological, social and economic problems (Kull et al. 201 4). la source de nombreux problèmes écologiques et économiques et The plant can reduce light and oxygen leading to deteriorating wa- affecte par conséquent les écosystèmes ainsi que les moyens de ter quality, increase water loss due to high evapotranspiration and subsistance des populations humaines des régions concernées. thus negatively affect the flora and fauna. Moreover it can hinder Elle est rencontrée au niveau des zones humides de l’Alaotra en- transportation, fishing and block intakes for hydropower and irri- globant le plus grand lac de Madagascar, le premier grenier à riz gation schemes affecting therefore the livelihood of local com- de l’île et qui tient une place importance pour la pêche. Les mé- munities (Calvert 2002). Furthermore, the water hyacinth thodes pour contrôler la prolifération des jacinthes d’eau represents a microhabitat for disease vectors (snails for bilharzia semblent ne pas pouvoir être appliquées à cause des limitations or Anopheles sp. for malaria) and therefore constitutes a threat to I Ecology and Environmental Education Group, Institute of Biology and Chemistry, Marienburger Platz 22, 31 1 41 Hildesheim, Germany II Madagascar Wildlife Conservation, Lot 1 4433 Atsimondrova, Ambatondrazaka 503, Madagascar III ETH Zurich, Ecosystems Management, Forest Management and Development Group, Universitaetstrasse 1 6, 8092 Zurich, Switzerland Citation Rakotoarisoa, T. F., Waeber, P. O., Richter, T. and Mantilla-Contreras, J. 201 5. Water hyacinth (Eichhornia crassipes), any opportunities for the Alaotra wetlands and livelihoods? Madagascar Conservation & Development 1 0, S3: 1 28–1 36. (doi:1 0.431 4/mcd.v1 0i3s.5) Madagascar Conservation & Development is the journal of Indian Ocean e-Ink. It is produced under the respon- sibility of this institution. The views expressed in contri- butions to MCD are solely those of the authors and not those of the journal editors or the publisher. All the Issues and articles are freely available at http://www.journalmcd.com Contact Journal MCD [email protected] for general inquiries regarding MCD [email protected] to support the journal Madagascar Conservation & Development Institute and Museum of Anthropology University of Zurich Winterthurerstrasse 1 90 CH-8057 Zurich Switzerland Indian Ocean e-Ink Promoting African Publishing and Education www.ioeink.com Missouri Botanical Garden (MBG) Madagascar Research and Conservation Program BP 3391 Antananarivo, 1 01 , Madagascar MADAGASCAR CONSERVATION & DEVELOPMENT VOLUME 1 0 | ISSUE S3 — OCTOBER 201 5 PAGE 1 29 human health (Masifwa et al. 2001 , Plummer 2005). ding hills are dominated by open grasslands and subject to Globally, a number of methods are used to manage and cont- continuous erosion. This leads to the reduction of the lake water rol the water hyacinth: the manual and mechanical control re- surface by sedimentation (Raharijaona-Raharison and Randrianari- quires high expenses. In China, removing water hyacinth comes at son 1 999, Wright and Rakotoarisoa 2003, Bakoariniaina et al. a cost of more than US$ 1 2 Million per year (Jianqing et al. 2001 ). 2006). In the last 30 years, Lake Alaotra has lost 5 km2 in size (Ba- Chemical control, using 2,4-D or glyphosate, is seemingly a more koariniaina et al. 2006). Fish catches (4,000 tons in 1 960 to economically feasible option. In the USA, chemical control is esti- 2,000 tons in 2004) are declining due to overfishing. Rice produc- mated to cost US$ 1 83 per hectare (Charudattan et al. 1 996). Ho- tion decreased by approximately 40% in recent years due to de- wever, in many countries public opinion is strongly against the use posits of sand and infertile laterite in poorly maintained irrigation of chemicals in water bodies, which are oftentimes used for drin- systems and deterioration of fertile soils (Pidgeon 1 996, Rakoto- king purposes (ibid). Biological control, though less widely applied, nierana 2004, Razanadrakoto 2004, Bakoariniaina et al. 2006). uses the weevil species Neochetina eichhornia, N. bruchi and the Consequently, reduced incomes are further exacerbating the moth Sameodes abligutallis which adults feed on water hyacinth pressures on the remaining marshlands. leaves and the larvae tunnel in petioles (Coetzee et al. 2009). Pa- According to Lammers et al. (201 5), the water hyacinth is thogens can also be used to control the water hyacinth. In Egypt, found everywhere on Lake Alaotra, building occasionally thick and the fungus Alternaria eichhornia was condensed in cottonseed oil dense mats spanning hundreds of square meters. The plant, ho- emulsion and spread on the water hyacinth killing 1 00% of the wever, is barely used in the region; a few people occasionally use plants seven weeks after application (Shabana et al. 1 995). Bio- it to produce compost, to feed pigs and geese and for installing control is economically feasible and environmentally viable but re- fish traps on the mats. It is currently unclear to what degree the quires several years of implementation (Charudattan et al. 1 996). water hyacinth in the Alaotra region is affecting local livelihoods As an alternative to mechanical, chemical or biological cont- (sensu Chambers and Conway 1 991 ), or whether the plant could rols, the economic utilization of this invasive plant has to be be used systematically and economically by a wider range of sta- considered. Globally, the water hyacinth is used in China, Indone- keholders. The objective of this study is to identify the potential sia, India, Malaysia, Bangladesh, Sri Lanka, Thailand, Philippines drivers and barriers to the use of water hyacinth

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